Opie's Job - S6-E1
Continuity mistake: When Aunt Bee walks by Floyd's shop the barber's pole is missing, but when Opie and Billy run across the street there's a red/white striped barber's pole, then when Andy walks by Floyd's shop the barber's pole has red/white/blue stripes.
Opie's Job - S6-E1
Continuity mistake: We see the exterior of the grocery/meat store a few times during this episode, and there are differences in things such as the actual facade of the building, the view through the doorway, etc.
Opie's Job - S6-E1
Continuity mistake: When Opie and Billy are both heading to the grocery store to apply for the job, the church is behind the boys and they're standing in front of the 'new and used furniture' store - both of which are to the right of the courthouse (when facing the courthouse), and to the left of the courthouse are the barbershop and the grocery/meat store.When the boys run across the street, they're coming from the opposite direction.
Answer: Those "boxes" are valences that used to be very common, before air conditioning. They allow for windows to be open during rain storms. They permit air circulation, without letting the rain in.